Peel shrimp, sautée peels for 5 minutes, then simmer for 20 minutes in 500ml of water to make shrimp stock.
Finely mince ginger and green onions, then fry them a bit in a little bit of fat. When the onions are soft and translucent, add curry paste and sauté for a minute.
Add coconut milk, tomato paste and shrimp stock to the pot and heat it up. Then put in the shrimp and as soon as they're all orange-like and done (after about 3 minutes) the soup is done. Add salt to taste.
Garnish with the green bits of the green onion.